Wednesday, July 2, 2014

There is a great deal we do not know about climate. People use this to contest greenhouse gas emissions policy but that is wrong-headed.

In real life, the more uncertainty one has about bad outcomes the more careful one is in taking risks.

In the climate world, uncertainty is used to urge continued and increasing risk-taking. This is backwards!

One thing we know for certain about changing the greenhouse gases in the atmosphere is that the climate cannot stay the same. That is very simple physical reasoning. Another is that the more we change the greenhouse gases the more it will change. And another is that we are already changing the greenhouse gases enough to matter.

Beyond that, there are many bad things that are more or less likely to happen, but the idea that it will all come out fine forever as we keep increasing the risk-taking smacks of delusion.

If scientists are overly encouraged by their institutions to get press coverage, there is a bias toward too much certainty and too much polarization. This may motivate people in the short run but only adds to dismissive skepticism in the long run.

What we should say is that while we understand a great deal about the climate system, it is very complicated and it's impossible to predict its exact behavior from one decade to the next. However, we know that we are forcing it into unprecedented configurations, and the more we do so, the crazier the risks we are taking.